Manufacture of tubes.



M. PETERS.

MANUFAGTURE 0F TUBES.

JAPPLICATION FILED JUNE 9, 1909.

Patented Feb. 8, 1910.

MATHIAS PETERS,

BENRATH, NEAR DUSSELDORF, GERMANY.

' l MNUFACTURE or rinans.v

ciencia Appucationpmed June e, 1909. serial No. 501,207.

specification of Letters Patent.

Patented Feb. S, i919..

` `mechanical engineer, subject of the `Grerman mandre the rolls.

Emperor, and `residing at Benrath,` near Dusseldorf, Germany, haveinvented a certain newand useful Improvement in the Manufacture'of Tubes, of which the following is a speciication.

The invention relates to the production of tubes; and particularly to a mill provided with several pairs of rolls, the successive rolls running at an increasing peripheral speed, having axes crossing one another and arranged .behind each other, and of ovalshtped or elliptical calibersin all pairs of ro ls.

1t has for its object to roll a inished tube which shall be materiall longer than the required mandrel, and o superior quality and to reduce the power consumption during the rolling, as well as to lessen the work required in stripping the inished tube from mandrel. I attainl these ob'ects by assing the work-piece through rol and in which the eccentricity or ratio of the distance of one focus from the center to one-half of the major axis of the ovalshaped calibers is the same throughout all Hubert@ rolling mnisfof this kind have been known with oval-shaped calibers only.

but of varying eccentricity for the various pairs of rolls; or, partly with circular and 'partly with oval-shaped calibers. In the first ty e of mill the friction between the and the work-piece is very great within the first slightly oval-shaped calibers, whereby, owing to this great friction, the inside portion of the workfpiece remains behind during therqlling process, causing distortions of same to arise, and-which ex- The'grooves, also, ofthe rollprovided to assist in taking main behind on the inside of same due t`o excessive friction between the' inner surface ofthe said work-piece and the mandrel, have to be renewed repeatedly as otherwise, owing to the congestion in the work-piece, breakages of spindles, rolls, &c., may be expected. In the second-type of mill menftOned, besides the draw-back of the formation of a seam, &c., due to the considerable reduction which must occur 1n the irst pair y drawing oif from ls as a oresaid this invention, the friction .left between the said rolls and which are of circular caliber, there is another inconvenience i. e. that the tube for its whole length incloses the mandrel, owing to the circular caliber of the last pair of rolls, in such a way thatthe tube during subsequent the mandrel within a mandrel-draw-bench, as-is well known, can be accomplished only by means of great force. I In this process the tube, owing to the great friction arising between the mandrel and the work-piece, will become much deformed and useless at that end which is being drawn against the abutment of the draw-bench.

The nature of my invention will be best understood in connection with the accompanying drawings, in which- Figures 1 and 2 are respectively a vertical and a horizontal section. Fig. 3 shows fragmentary sections of the work-piece, mandrel and rolls.

Similarcharaoters of reference designate corresponding parts throughout the several views.y

In the drawings, a designates the pairs of rolls, which `are set alternately at right angles to each other and eachds'ucceeding pair being driven 'at an increasing peripheral speed. The rolls are all of oval-shaped caliber,l and the eccentricit thereof is the same throughout all thel rol s,

b designates the workpiece within which is a mandrel c. A

Owing to the equal eccentricity for all pairs of the oval-shaped rolls a, according to between the mandrel c an the work-piece b will be reduced as muc` as possible, because the tube of oval-shape section comes into contact with the periphery of the mandrel always only in two places, and therefore easily slides overV the same. The consumption of the power of the mill will thus be lessened, 'and thev work-piece will be protected against the s ,imita rien.

great injurious strain mentionedA before, so

that the tubes produced will bemuch superior in quality, especially as regards thicknes's of wall. The speed, also, of the mandrel would tend Vto change from one air of .rolls to the other in touching and eavlng with the work-piece the said rolls, that-is to say the mandrelA adopts a speed which isthe most favorable one to the tube to be rolled.

greatest stress. lipon thawork-pece and. the mandreLad as the' movement of the man- -reiat'er tlan the peripheral speed. ofv the rst .pairs ofv rolls. In aE rollin mill of the kind set' forthftherefore, thel nished tube" will? bei 1nater-iall-yl' longer? than: th required' nfmin lrel=r Icla-im: L v 1.-.J'Ih'efr'xanu'acture` of tubes in all milillhaving a; seriesY of sets- 'of rollsv with passes arjranged" in alinement With'tlfie aires of't suc-v ees'svf arranged' at right; angles; which.

" 'comastfs in subjecting' a work piece assemel were a mandrel. whicr i's permitted: to move alon with the workpiece to a1 con-y 'ngactijonidn sfad mill, the .passes tinnou's; rol

. inthe different setsg of so constructed che eine ofr and arnanged that thewo'rk piece will be sj'ected tioa reducing pressure on opposite sides amd allcwedl' tofseparate from the mandrel at substantially right angles eatest reduction, the portions' o the wor i piece wl'liclflz are reuced and permitted toA separate' from the;

,-.reducedin the succeeding pass.A 2.. The manufacture of cnbes in -ay vmill having'a series of sets of'rollsforming substantially complete elliptical passes Whose ec- .centricities are the same and arranged in alinementwith the a-Xes of successive-sets arranged at right angles, Which consistslin subjecting aL Worl'rf piece assembled over` a mandrel-Which is permitted to move-'along with the Work `ieee-'to a continuous' rolling action in saidm1l1l, the passesjin thed-i-H'e'rent sets 4of rol-'ls all: soconstructed' and arranged, tha-tthework pice be subjected to" a reducing pressure onoppositeisides andi' will be all'ovvfel?v to.'t separate romthe mandrelat i'substantially rightangles' fromthef point of@A the portions of' che world .greatest reduction, f piece which; arereduced and-'permitted to Iseparate' from.; the: mandrel one pasar-.ba` g ing .respectiifely permittedV toi separate from' the; mandrel'- andlf rewlfnceilt inf the? scceedng pass In: testimony' whereof I have signed mfy: fg name tothe specircatioir the'v preseneeof' two subscribing. fyvitnesses.. v

' MATTHAS- .PEKIAERSL Witnesses: I

WmmsyVaNnoer;

mandrel' onepass beil'igrzg' respectively per# BEssmf F.

mitfedjm separare )emm-y t'h mamma; mi'l 

